摘要目的 分析北京市HIV 1 B亚型的分子流行特征.方法 采集北京市2006年至2010年新发现的HIV 1 B亚型感染者抗凝血,反转录-套式PCR扩增病毒gag基因,并进行系统进化和Entropy核苷酸多态性差异分析.结果 成功扩增167份标本,其中欧美B亚型10份,B'亚型54份,中国B亚型101份.B'亚型进化簇内存在多条来自泰国和印度的序列,中国B亚型独立成簇,进化簇内无其他国家的序列.中国B亚型存在4个亚簇,71.1％的病例为男男性传播.以欧美B进化簇为参照,B'亚型和中国B亚型进化簇分别存在55和9 4个有明显差异的核苷酸位点.结论 北京市存在3种类型的HIV-1 B亚型,其中1种为本土株.

abstractsObjective To analyze the molecular epidemiological characteristics of human immunodeficiency virus 1 (HIV-1) B subtype strains in Beijing.Methods Plasma samples were collected from 200 newly diagnosed HIV 1 B subtype individuals reported during 2006 to 2010 in Beijing.The gag gene fragments were amplified from RNA template extracted from plasma using reverse transcriptation and nested polymerase chain reaction (PCR) methods and the sequences were analyzed by phylogenetic and Entropy analysis.Results A total of 167 sequences were successfully amplified from the gag genes.Phylogenetic analysis indicated that the subtype B sequences in Beijing could be grouped into three clades,which were named Europe and America B clade (10 sequences),B' clade (54 sequences) and China B clade (101 sequences) based on the origin of the reference sequences.China clade was pure Chinese B subtype clade which did not contain any foreign strains and it was segregated into four major distinct clusters,of which 71.1 ％ individuals was men who have sex with men (MSM).When compared with Europe and America clade,there were 55 and 94 significantly different nucleotides polymorphism composition sites in B'clade and China clade,respectively.Conclusion Three main epidemic clades exist in HIV1 B strains in Beijing,including one local China B clade.